Prayer is the first thing
for which a person will be brought to account on the Day of Judgement. The
Prophet (peace and blessings of Allaah be upon him) said: “The first
thing for which a person will be brought to account on the Day of
Resurrection is his prayer. If it is sound then he will have succeeded, but
if it is not sound he will be doomed.” Narrated by al-Tirmidhi, 413, Abu
Dawood, 864; classed as saheeh by al-Albaani in Saheeh Abu Dawood.

Allaah erases sins by means
of prayer and raises people in status thereby. It is the last religious
commitment to be forsaken and if it is neglected then all religious
commitment is lost. See question no.
33694.

My brother, adhere to
regular prayer before you die… pray before the funeral prayer is offered for
you.

If you are already praying
regularly, then continue to do so. If you have been negligent about prayer,
then repent and seek forgiveness before it is too late. Whoever turns to
Allaah, Allaah will turn to him.

Allaah says, according to
the hadeeth qudsi: “If he draws near to Me a hand span, I draw near to him
an arm’s length, and if he draws near to Me an arm’s length, I draw near to
him a fathom’s length, and if he comes to Me walking, I go to him at speed.”
Narrated by al-Bukhaari, 7405; Muslim, 2675.

So repent sincerely to
Allaah, and Allaah will accept your repentance.

Secondly:

Being careless about prayer
and delaying it until the time for it is over with no excuse is a major sin.
See question no. 47123.

Some of the scholars are of
the view that the one who omits a single prayer with no excuse until the
time for it is over is to be viewed as a kaafir. See question no.
39818. This is the
view on which the answer to your question is based, which is the command to
the one who omits a single prayer with no excuse until the time for it is
over to do ghusl.

That is because it is
prescribed for a kaafir who becomes Muslim to do ghusl, as it is also
prescribed for an apostate who returns to Islam.

Shaykh Ibn ‘Uthaymeen said
in al-Sharh al-Mumti’ (1/202):

If a kaafir becomes Muslim,
he has to do ghusl whether he is new to Islam or had apostatized.

“New to Islam” means one
who formerly belonged to another religion all his life, such as a Jew or
Christian or Buddhist, etc.

“Had apostatized” means
that he had been a Muslim, then he apostatized from Islam – we ask Allaah to
keep us safe and sound from that – such as one who did not pray, or thought
that Allaah has a rival or partner, or prayed to the Prophet (peace and
blessings of Allaah be upon him) seeking his help at a time of hardship, or
prayed to someone else seeking his help in a matter in which he could not
help.

The evidence that ghusl is
required in such cases is as follows:

1 – The hadeeth of Qays ibn
‘Aasim, who said that when he become Muslim the Prophet (peace and
blessings of Allaah be upon him) ordered him to do ghusl using water and
lotus leaves. Narrated by al-Tirmidhi, 605; classed as saheeh by al-Albaani
in Saheeh al-Tirmidhi. So the basic principle with regard to this
matter is that it is obligatory.

2 – He has cleansed himself
inwardly from the filth of shirk, so wisdom dictates that he should cleanse
himself outwardly by doing ghusl.

Some of the scholars said
that he does not have to do ghusl, and they quoted as evidence the fact that
no general command was narrated from the Prophet (peace and blessings
of Allaah be upon him), such as saying whoever becomes Muslim let him do
ghusl, as he said, “Whoever comes to Jumu’ah, let him do ghusl.” How many of
the Sahaabah become Muslim but there is no report that he told them to do
ghusl or said, whoever becomes Muslim let him do ghusl. If it were
obligatory it would have been well known because the people need to know
about it.

We could say that the first
view, that ghusl is required, is stronger, because the Prophet (peace
and blessings of Allaah be upon him) issued a rule to one member of the
ummah for which there is no reason to assume that it applied only to him, so
it may be assumed that it applies to the ummah as a whole. The fact that the
Prophet (peace and blessings of Allaah be upon him) issued the command
to one person does not imply that he did not issue the same command to
others as well.

With regard to the fact
that it is not narrated from each one of the Sahaabah that he did ghusl when
he become Muslim, the fact that there are no reports does not mean that it
did not happen, because the basic principle is to do that which the Prophet
(peace and blessings of Allaah be upon him) commanded, and it is not
essential for there to be a report from each person who did it.

Ibn Qudaamah said in
al-Mughni:

If a kaafir becomes Muslim
he has to do ghusl, whether he is new to Islam or had apostatized… this is
the view of Maalik, Abu Thawr and Ibn al-Mundhir.

It says in al-Mawso’oah
al-Fiqhiyyah (31/206):

The Maalikis and Hanbalis
are of the view that a kaafir’s becoming Muslim necessitates ghusl. If a
kaafir becomes Muslim, he must do ghusl. They did not make any distinction
between a kaafir who is new to Islam and one who had apostatized. Ghusl is
also required of an apostate who comes back to Islam.